Fuel injection device



June 17, 1958 J. FAusT 2,839,000

FUEL INJECTION DEVICE Filed Feb. 11, 1954 s Sheets-Sheet 1 F/G. I

//V VENTOR 2/:10/ ift b/ J1me 1958 J. FAUST 2,839,000

FUEL INJECTION DEVICE Filed Feb. 11, 1954 3 Sheets-Sheet 2 Winn.

QdLQA June 17, 1958 Filed Feb. 11, 1954 J. FAUST FUEL INJECTION DEVICE 3Sheets-Sheet 3 United States. PatentO FUEL INJECTION DEVICE Josef Faust,Sieghurg, Germany, assignor to Kliickner- Humboidt DeutzAirtiengesellschaft, Koln-Deutz, Ger

many 1 Application February 11, 1954, Serial No. 409,609

Claims priority, application Germany February 14, 1953 3 Claims. (Cl.103-5) The present invention concerns a fuel injection device and, moreparticularly, relates to a fuel injection device for internal combustionengines in which an ejector actuated by the overflow fuel of theinjection pump acts as feeding pump, and in which the overflow conduitof the fuel injection pump is, in a manner known per se, separate fromthe intake conduit.

Witha heretofore known fuel injection device of the above mentionedtype, a nozzle serves as ejector, which nozzleconcentrically leads intoa diffuser having an inner circular cross section. The manufacture ofsuch ejector causes considerable difficulties in view of the precisionrequired because its efficiency is already considerably affected if, forinstance, the nozzle is not precisely concentrically arranged withregard to the diffuser.

It is an object of this invention to provide a feeding means for a fuelinjection device of the above mentioned type which will be considerablysimpler in construction and easier to manufacture than thecorrespondingfeeding means heretofore known in connection with such fuelinjection device.

It is a further object of this invention to provide a fuel injectiondevice of the type set forth above which willrequire considerably lessspace than fuel injection devices as heretofore known for similarpurposes, and which'will not require the employment of feeding nozzles.

These-andother objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings in which: I

Fig. 1 is a diagrammatic representation of a fuel injection installationaccording to the invention. I

Fig. 2 illustrates on a larger scale than Fig. l the connection offeeding means according to the invention with a fuel filter shown inFig.1.

General arrangement The feeding means according to the present inventionis characterized primarily in that one or more passages or channels forconveying the overflow fuel lead into the feeding conduit means at anacute angle so that the desired flow as well as the desired direction offlow will automatically be obtained in the said feeding conduit means sothat neither nozzles nor diffusers in cooperation with nozzles will berequired.

The effect of this feeding means or feeding device is based on the factthat each time a short severe pressure shock is being produced in thefuel injection pump by the overflow of the fuel, a pressure wave will beproduced in that section of the feeding conduit means which is adjacentto the feeding-in range in the feeding direction. 7 This pressure wave,putting into motion the liquid 2,839,000 Patented June 17, 1958 IC C 2in said conduit section, acts like a piston and draws with it liquidfrom the space preceding the feeding-in range.

According to a particularly advantageous arrangement in conformity withthe invention, the passages or channels which conveythe overflow fuellead into the feedingconduit means at an angle of less than 30".

In order to prevent an interruption in the delivery fiow of the fuel inthe feeding conduit means during the intervals between theoverflow-periods of the feeding pump, the feeding conduit meansisdesigned so long that the inertia effect of the fuel contained thereinwill overcome the said intervals between the overflow periods. The ratioof the length of thatsection of the feeding conduit means which followsthe feeding-inrange for the overflow fuel with regard to the innerdiameter of this section of the conduit means preferably amounts to atleast :1; Furthermore, also the ratio of the cross section of the mixingdistance following the feeding-in range with regard to the feeding-incross section of the overflow fuel is of importance. A ratio of 3:1 hasbeen found'to yield good results.

The feeding-in of the overflow fuel may be effected directly into thefeeding conduit means or according to a still further development of theinvention may be effected within a special feeding element which isbuilt into the feeding conduit means and is provided witha connectionfor the overflow fuel. ,The said feeding element'consists primarily of abody within which the feeding-in of the overflow fuel is effected into abore leading off from the entrance opening for the fuel to be delivered,and of a preferably coil pipe which connects the said bore with the fuelexit opening.

If desired, also other auxiliary means such as check valves, adapted toincrease the efficiency may be incorporated in the feeding device.Thefeeding device is preferably directly connected to the fuel filter orto the fuel injection pump. The coil pipe when forming a component ofthe feeding device is preferably mounted in a recess provided'in thecasing of the fuel filter or the fuel injection pump.

The installation in a small chamber of such a section of the conduitmeans as is required' for a good effect, for instance by winding suchsection in form of a coil or by enclosing the conduit section ina-casing of the fuel filter or fuel injection pump, hasthe advantagethat a damaging of such condiut section will be prevented and, when'repairing the device, a replacement of such conduit section by' ashorter section will be obviated.

Structural arrangement Referring now to the drawings in detail and Fig.1 thereof in particular, the arrangement shown therein comprises a fuelreservoir 18 from which the fuel passes through conduit 19, a valve'13,a filter 20, and a conduit 21 into the cylinder 16 of a fuel injectionpump 17 After the piston upper edge 22 of the fuel injection pump 17 hasclosed the mouth of the suction conduit 21, the fuel injection pump 17feeds fuel through the pressure or check valve 23 and pressure conduit24 through the intervention of the fual injection valve 25 into thecombustion chamber of an engine. The fuel injection is completed as soonas the control edge 27 of the piston of the fuel injection pump 17releases the mouth of the overflow conduit 15 in the fuel injection pump17. The overflow conduit 15 leads at 29 at an acute angle a ofpreferably 30 into the suction conduit 19.

As will be evident from Fig. 1, the overflow conduit 15 feeds into thesuction conduit 19 ahead of the filter 20 when looking in the directionof flow of the fuel to the injection pump 17.

In conformity with the specific showing of Fig. 2, the feeding in of theoverflow fuel is effected within a special feeding element or block 1.The inlet opening 2 of the arrangement shown in Fig. 3 is connected tothe conduit 19 shown in Figs. 1 and 2. The discharge opening 3 in thearrangement of Fig. 3 for the fed fuel is connected to the conduit 21shown in Figs. 1 and 2.

The openings 2 and 3 are interconnected through a bore 4 (Fig. 3) havingone end adjacent to and in communication with the opening 2 and havingits other end connected to a coil pipe 5 communicating with the opening3. The fuel passed into the feeding device from the fuel injection pumpthrough the overflow 15 (Figs. 1 and 2) flows into block 1 through anopening 6 (Fig. 3) and from there passes through an oblique channel 7into the bore 4 and from there into the coil pipe 5. Due to the pressurewaves which occur within theifeeding-in range of the bore 4 and whichcontinue into the coil pipe 5, liquid is intermittently drawn in fromthe intake opening 2. A flowing back of the liquid into the feederconduit 9 which is connected to the block 1 by means of a hollow screw 8and nut 8a is prevented by a check valve 10 arranged in said hollowscrew.

Fig. 4 diagrammatically illustrates a portion of a fuel injectioninstallation according to the invention with the feeding means mounteddirectly on the fuel injection pump. In Fig; 4, the tank is againdesignated with the reference numeral 18 and furnishes fuel throughconduit 19 and block 1 into the coil 5 similar to the arrangement ofFigs. 2 and 3. The overflow conduit is designated with the referencenumeral 15, while the filter is again designated with the referencenumeral 20.

The operation corresponds to that described in connection with Figs. 1to '3.

It is, of course, understood that the present invention is, by no means,limited to the particular arrangement shown in the drawings but alsocomprises any modifications within the scope of the appended claims.

What I claim is:

1. In combination in a feeding arrangement for use in connection with afuel injection pump having a fuel intake opening and an overflow openingand being arranged for supplying fuel to an internal combustion engine:a fuel reservoir, a body provided with first conduit means, a fuelfilter having a casing with a recess therein and also having an inletconnected with said fuel reservoir, said fuel filter also having anoutlet connected with one end portion, of said first conduit means forconveying fuel thereto, said body being provided with second conduitmeans having one end portion thereof connected to said intake opening ofsaid pump for discharging fuel thereinto, connecting means effectingcommunication between the other end portions of said first and secondconduit means, said connecting means being formed by coiled conduitmeans mounted in said recess of the casing of said filter, and thirdconduit means having one end portion thereof connected to said overflowopening for receiving overflow fuel from said fuel injection pump andhaving its. other end portion leading into said first conduit means atan acute angle with re- 'gard to the longitudinal axis of said firstconduit means so that the legs of said angle open in a directionopposite to the desired direction of flow of fuel in said first conduitmeans toward said fuel intake opening.

2. In combination in a feeding arrangement for use in connection with afuel injection pump having a casing with a recess and also having a fuelintake opening and a fuel overflow opening for supplying fuel to aninternal combustion engine: a body provided with first conduit meansarranged for connection with a fuel reservoir, said body also beingprovided with second conduit means including a discharge opening fordischarging fuel to be delivered to said fuel intake opening, coiledconduit means arranged in said recess of the casing of said fuelinjection pump and effecting communication between said first and saidsecond conduit means, and third conduit means having one end portionthereof arranged for connection with said overflow opening for receivingoverflow fuel from said fuel injection pump and having its other endportion leading into said first conduit means at an acute angle withregard to the longitudinal axis of said first conduit means so that thelegs of said angle open in a direction opposite to the desired directionof flow of fuel in said first conduit means toward said fuel intakeopening.

3. In combination in a fuel injection device: a fuel injection pumphaving a fuel intake opening and a fuel overflow opening, an ejectorassociated with said injection pump and operable as a feeding pump bythe overflow fuel of said injection pump, delivery conduit means havingone end arranged for connection with a fuel supply and having its otherend arranged for connection with the fuel intake opening of said fuelinjection pump, and additional conduit means having one end portionthereof connected to said fuel overflow opening for receiving overflowfuel from said fuel injection pump and having its other end portionleading into said delivery conduit means at an acute angle with regardto the longitudinal axis of said delivery conduit means so that the legsof said angle open in a direction opposite to the desired direction offlow of fuel in said delivery conduit means toward said fuel intakeopening, the ratio of the length of the delivery conduit means followingin the direction of flow the feeding-in point of said additionalconduit'means into the delivery conduit means to the inner diameter ofsaid section being at least :1.

References Cited in the file of this patent UNITED STATES PATENTS1,958,354' Stephens May 8, 1934 2,230,201 Hermann Jan. 28, 19412,263,913 Bargeboer Nov. 25, 1941 2,297,681 Anderson et al. Oct. 6, 19422,495,685 Beaman Jan. 31, 1950 2,657,637 Baker Nov. 3, 1953 FORElGNPATENTS 49,609 Austria of 1909 382,592 Great Britain Oct. 27, 1932

